Yes - if you press F1 once a tooltip popup shows, if you press it again it moves to a separate window.
The problem seems to be related to some confusion about which clojure.core to use.
For those vars that are missing the docstring, navigating to definition throws up this somewhat mysterious dialog:
Of note this is from a .cljc file -- so either Clojure or ClojureScript could be considered the definition.
The problem does NOT happen in a .clj file.
So my theory is that because Cursive is not sure which runtime to pick, it defaults to choosing neither for the docstring.
I'd rather it just take the Clojure one FWIW.
"ish" is an option (twice)... according to clojure -Stree it is transitively included by scicloj/noj and my guess is that it is an uberjar containing clojure and clojurescript.